Sudden swelling lump on neck?

Ok, so follow up on the lump. It`s about an inch and a half long, 1 inch high. I`m not sick, have no symptoms other than stiffness is my neck due to the swelling and a slight sorness. I don`t have acne, and there is no open wound so there`s no pus or any drainage. The only thing I can think of it being is swelling from wearing a tight strap around my neck yesterday but I don`t know that that would cause a lump? Also it wouldnt explain the previous two that I had a week ago that went away within 3 days.